The present invention relates to an optical receiver.
In conventional circuits, an optical-to-electrical transducer is followed by an automatic gain control amplifier which compensates for variations in the received light level and amplifies the latter to a level required by a following signal regenerator to restore the signal to its original form. Such an amplifier is disclosed in DE-OS No. 32 33 146. However, considerable difficulties are encountered in the design of the amplifier if both high sensitivity and a large control range are required. To be able to process high light levels, a variable optical attenuator to be mechanically adjusted to the respective attenuation value required is therefore placed ahead of the optical-to-electrical transducer. This, however, entails a considerable loss of sensitivity.